How to determine air heating power in kW

[dairytech]

Hi, I have been experimenting with evacuated tubes for heating air and am having some half reasonable results.

What I want to do is be able to put an actual power figure on each run to see what improvements I can make.

Can anyone point me to a formula or method for working this out please ... and if it uses centigrade rather than farenheit would be an advantage too. ;) Thanks.

[frank]

Here's a link to a YouTube channel that explains heat transfer very well. Check out his other vids as well. https://youtu.be/bRZwzy0xvhM

[dairytech]

Thanks for the link Frank. I watched a few of his videos and then one of the suggested videos gave some answers, though still using farenheit and BTUs.

I replied over the weekend but it obviously didn't save because it's not here.